Question

I want to create a rake task that will run automatically every seven days (sunday at midnight), that will analyse a weeks worth of data (at max 20,000 records per week).

An Outlet has_many :monitorings
A Monitoring belongs_to :outlet

I want to check if at the end of the week an outlet has had a minimum of 4 records created. If not, I want a record to be created inside of the DB in a table called unmonitored.

The record should contain the the number of times it has been monitored and the week start and end dates.

Answer 1

To run a rake task periodically, you can use bare cron jobs or a nice ruby wrapper, Whenever.

Take a look:

every 3.hours do
  runner "MyModel.some_process"       
  rake "my:rake:task"                 
  command "/usr/bin/my_great_command"
end

every 1.day, :at => '4:30 am' do 
  runner "MyModel.task_to_run_at_four_thirty_in_the_morning"
end

every :hour do # Many shortcuts available: :hour, :day, :month, :year, :reboot
  runner "SomeModel.ladeeda"
end

every :sunday, :at => '12pm' do # Use any day of the week or :weekend, :weekday 
  runner "Task.do_something_great"
end

every '0 0 27-31 * *' do
  command "echo 'you can use raw cron syntax too'"
end